I shoot with 120 Pan F fairly often developed in Rodinal and I follow the times recommend on the Massive Development Chart.

I do however modify their recommendations a tad in that I develop slightly colder than 68 degrees (usually 66), increase my time a little bit, and I agitate very gently to tame the contract, particularly when I know my lighting was contrasty. When shooting on an overcast day I just develop as normal.